Commercial mowers typically utilize reel type mowing units which must be maintained regularly to assure proper operation. Part of such maintenance involves sharpening the blades and adjusting the bed knives. The sharpening process typically involves two steps: First spin grinding the tips or radial ends of the blades in order to `true` the reel back to cylindrical shape, and then relief grinding the trailing edge of each blade in order to assure proper contact with the bed knife. This is a manually intensive, time consuming process.
Commercial grinders for this purpose have been available heretofore from Foley United, a division of the assignee hereof, Foley-Belsaw Company, and other manufacturers. However, the grinders of the prior art have typically required numerous and complex adjustments for proper setup, especially in the relief grind mode, depending upon the configuration of the particular mowing unit. Mowing units from different manufacturers have various sizes, number and size of blades, direction of blade twist, etc. As a result, it has been necessary to setup, adjust and then relief grind each blade in the reel of the mowing unit. This is labor intensive and time consuming. Also, it has usually been necessary to first remove the cutting reel from the mowing unit to access the blades for grinding.
More recently, improved grinders have become available. For example, U.S. Pat. No. 5,321,912 to Neary shows a mower reel blade relief grinding device incorporating on a common drive shaft separate slideable grinding wheels, one of which is used in the spin grind mode and the other being used in the relief grind mode. However, this device still requires complicated setup and re-adjustment on a blade-by-blade basis in the relief grind mode.
Heretofore, there has not been available a mower reel grinder which is adapted for automatic indexing so that each of the blades can be relief ground in sequence without further operator attention after initial setup.